New Video of Antarctic Crack

February 21, 2017

It’s summer in Antarctica, which has scientists scurrying around the seventh continent carrying out various research experiments. That includes monitoring the massive crack that has spread across the Larsen C ice shelf, located on the Antarctic Peninsula.

On Tuesday, researchers with the British Antarctic Survey released new aerial footage showing the widening rift that threatens to tear the ice shelf asunder at any moment. The footage makes the immensity of the crack clear, as the yawning chasm stretches off into the horizon.

The crack now stretches more than 100 miles in length. And at 1,500 feet across, you could lay the Empire State Building across the rift with a few feet to spare.

The rift is expected to soon cleave a monster iceberg off the Larsen C ice shelf. Scientists estimate the iceberg could be up to 1,930 square miles in size, or roughly 10 percent of the whole ice shelf. That’s the equivalent of Delaware (or twice the size of Wales if you prefer Commonwealth measurements).

Scientists at Project MIDAS, an Antarctic research group monitoring the rift, wrote in January that the breakup “will fundamentally change the landscape of the Antarctic Peninsula” and leave the ice shelf in a less stable state.

That could eventually cause it to collapse, a fate that befell the Larsen A and B ice shelves in 1995 and 2002, respectively. The Project MIDAS scientists wrote that the Larsen B breakup followed a similar massive iceberg calving event, which was caused by abnormally warm air in one of the world’s fastest warming places.

Ice shelf health is a key metric researchers are watching all around Antarctica. The shelves act like bookends, holding up the massive stores of ice on the continent. If they disappear, it will cause more land ice to tumble into the ocean, raising sea levels. Since Larsen B’s collapse, the glaciers behind it have flowed to the sea six times faster.

The West Antarctic has some shelves very vulnerable to breakup, including the Pine Island Glacier ice shelf. It recently calved a comparatively small “aftershock” iceberg following a major July 2015 calving event. But satellites show that it has started to develop a large crack as well.

Previous research has shown that an unstoppable melt that would drive oceans at least 10 feet higher could already be underway in West Antarctica, though it would take centuries for the process to play out. Warming oceans and air are the main culprits.

How many gigatonnes of ice must melt to raise the oceans one millimeter (10-3 meters)?
The number of gigatonnes of water that must be added to the oceans to raise the sea level 1 millimeter is given by:

The iceberg doesn’t need to melt to add to SLR, it just needs to break off (like ice cubes in a glas of water). In other words every metre of the 1,930 square miles which is above sea level would add about 14 micrometres. Respectively 100 metres would add about 1.4 millimetres to SLR.

Sea-level is not affected directly by the fragment breaking away from Antarctica, as the fragment is already floating on the ocean. The breakup will however leave the remainder of the shelf more vulnerable to future collapse. If all the ice that the Larsen C shelf currently holds back were to enter the sea, it is estimated that global waters would rise by 10 cm (3.9 in).[26]

“Sea-level is not affected directly by the fragment breaking away from Antarctica, as the fragment is already floating on the ocean.”

I think that’s not correct. Ice isn’t rubber. But as soon as the ice is breaking off the land it is adding most of its part which is above the water line (it doesn’t need to melt) to the sea level. Currently about half of SLR is due to thermal expansion. So the breaking fragments are adding to this expansion.

1. Sir Charles is entirely wrong in thinking that ice berg calving in itself raises sea levels. As Jefferey Green has repeatedly said, the ice shelf is already floating on the water so whether or not it is attached to land is irrelevant to sea level. When water freezes it expands – as everyone know – and that is why one ninth of the volume of ice in the sea will be above the surface. When it melts, the volume will contract again – all of it. So it is not only the ice above the surface that contracts but also the ice below the surface. The net result is that it makes no difference whatsoever to sea levels. If you don’t believe that try it yourself at home; pour some water at a temperature a little above freezing into a container and mark the surface level. Then add some ice carefully, not too much or too little. Now mark the surface level again. Then wait until all the ice has melted. Has the surface level risen again? NO, of course it hasn’t. This nonsense is typical of the lies being told about global warming in this so-called scientific age.

2. If the calving of Larsen C leads to the ice in inland glaciers moving faster into the sea – which is by no means certain because there will still be 90% of the shelf left – then that will lead eventually to sea level rise (all other things being equal) but this is ice coming from a very thin peninsula and flowing into the one part of the Antarctic Ocean that remains frozen all year round. What will happen in practice is that the ice shelf will grow again, and then collapse again. The extra water that will add to global sea levels will be very little and very slow. Look at the reality at https://seaice.uni-bremen.de/sea-ice-concentration/ and take into account that while Antarctic West is warming, the much larger Antarctic East is cooling and you will realise that this Larsen C ice shelf is totally insignificant to global effects. This is all hysteria whipped up by ignorance.

2. “the much larger Antarctic East is cooling”. The link you posted doesn’t support your claim. There is one study out (NASA) which came to the conclusion that the Antarctica would be gaining ice. Though the researchers couldn’t explain current sea level rise with their findings. The study has been disputed in the scientiic community.

@Sir Charles You obviously don’t understand the use of the word “calving” as applied to icebergs. It is only applied to ice shelves or to larger, less regular, icebergs that have already become floating at the end of a glacier. In the case of Larsen C it is a shelf, You can see clearly in the many photographs that is is flat on top – hence the name “shelf.” It has spread out like that with a flat top precisely because it is floating on the sea beneath. It is cracking precisely because incoming waves from the open sea are impacting the shelf from beneath. When the crack reaches an edge with the sea at the other end, that whole section will float away. Over time it will melt and will make no effect whatsoever on sea levels.

The point of the link was to show two things: first that that small thin peninsula is very small in contrast to the whole of Antarctica and therefore a minnow in this game; second that although the photographs show open sea beyond the ice edge, in fact the Larsen C shelf discharges into the Weddell Sea which remains frozen for the whole year and thus poses a further barrier to ice moving further out to sea.

What current sea level rises? Because land moves up and down as well as sea (for example Scandinavia is still rising as a result of shedding the huge weight of the Glacial Phase ice) there is no point on earth which can be used as a comparison marker. Thus is some places seal levels appear to have risen, but not so in others. London is sinking because of the huge weight of a city built on clay, not because of rising seas.

Re “the much larger Antarctic East is cooling” the pictorial in a Wiki entry about some argument about East Antarctica warming or not shows a larger area of East Antarctica warming than cooling during the last 50 years as judged by my blood-shot eye balls from the water/ice/vodka experiment. I’m quite interested so point to the analysis that shows East Antarctica cooling over the last 50 years, or the last 30 years, or the last 15 years, or the last 5 years, or since this Tuesday at tea time, or whatever unstated time scale your reference analysis was using.

Anyone who wants to see what a bald-faced liar and distorter of reality Peter Irvin is need only google “antarctic warming and ice melt” and turn their blood-shot eye balls (if they’ve been doing the water/ice/vodka experiment) to the many hits there, a lot of them from Climate Central. PI’s “reference analysis” is just made up or distorted BS from the deniers manual, and has NO connection to the reality of what is happening.

Poor Vierotchka! Here she is, trying to “play nice” and talk science for a change, and what happens? Some well-meaning Crockers make some replies that will likely mislead and confuse her. Anyone who asks “…. how much will sea levels rise once it has completely melted?” doesn’t understand the science and deserves better. Indy222’s answer of “0” is the best answer anyone gave—-simple and direct. JefferyG’s last comment and Peter Irvin’s gave mostly correct info but may cause “information overload” for V.

The problem here is that most people don’t fully understand the concept of DENSITY and the D = M/V relationship (as well as the concept of displacement and “floating”). I seems simple but many high school physics students had trouble with it. The problem is made worse by the fact that water is one of the very few substances where the solid phase (ice) is LESS dense than the liquid phase—-most things shrink uniformly in volume as they get colder and therefore get more dense, i.e., same M in less V gives greater D.

With the exception of temperatures from 0 to 4 degrees Celsius (typical of the waters where icebergs calve and begin to melt), the density of water decreases as the temperature rises and also decreases as the temperature falls. That means an iceberg floats higher out of the water between 0 and 4 degrees than it does at temps high or lower than that, and highest where water is most dense at ~4 degrees C (~39F).

Jeffery’s first comment is flat out wrong. “We would need to know the volume of ice above the water. The ice below the water has already displaced the ocean”. It’s the weight of the entire block of ice that is doing the displacing, and how much of it is above or below the water is irrelevant—-that will change slightly as the temperature of the water changes, but when it all melts it will produce as close to ZERO as you can get change in seal level.

Not quite sure what Sir Charles is getting at, but ice is “rubbery” in that it flows and changes shape. I think it’s a bit unfair to SC for Peter I to say “This nonsense is typical of the lies being told about global warming in this so-called scientific age”. Confusion happens to the best of us—lies are deliberate.

Same goes for Peter I’s paragraph 2). IMO, “This is all hysteria whipped up by ignorance” is also flat out wrong. ANY ice shelf that loses 10% of its volume will NOT be able to hold back the glaciers feeding it as well, and the concern is more with the much larger quantity of land ice in the West Antarctic (latest studies show that any small growth in the east is far overshadowed by losses elsewhere, and that the glaciers in the east are starting to become worrisome). Rignot and the others are not hysterical—-reread the last paragraph of the post—-and just because they don’t understand it all and can’t come up with a precise timeline doesn’t mean they are ignorant. And the Arctic is where our focus should be anyway—-that’s where the serious shorter-term tipping points are lurking.

@dumboldguy Although Greenman610 does slip in an admission that “This will take centuries to play out” the whole tone of this minor event in an unimportant corner and talk of “an unstoppable melt” is very fairly described as “hysteria whipped up by ignorance.” In fact those 7 words remove any point or meaning from his whole post.

Your own comment admits and both Sir Charles and vierotchka demonstrate that many people are ignorant of the forces at play and are easily misled by those who are being paid huge research grants to feed the global warming machine.

You are absolutely right in saying that the focus should be on the Arctic for it is there that we can see that Planet Earth is almost at the end of the inter-glacial phase of the current, 2.5 million year old, Ice Age. After the short inter-glacial phase it always, and suddenly, swings back to start the much longer glacial phase. That’s the process; why should a bit of extra CO2 change that?? As I said, “hysteria whipped up by ignorance.”

Don’t try to put words in my mouth and distort my meaning with “Your own comment admits….” and the total bullshit contained in your last paragraph . Same goes for Peter’s words, i.e.—- “Greenman does slip in an admission that “This will take centuries to play out” the whole tone of this minor event in an unimportant corner and talk of “an unstoppable melt” is very fairly described as “hysteria whipped up by ignorance.”

You have again shown your true colors as a denier with this whole comment—-your efforts to distort and misinterpret the “seven words” are obvious to all. You may now be “fairly described” as a sneaky and lying denier SOB who thinks he is smarter than the average Crocker and can therefore treat them with disrespect.

The planet SHOULD be nearing the end of the current inter-glacial, but the evidence is that AGW has short-circuited the process, and it is precisely the “bit of extra CO2” and other GHG that have contributed to AGW that appear to have delayed if not actually cancelled the next ice age (and your 2.5 million year figure is misleading also).

Are you a paid whore for fossil fuels like Russell Cook? What’s your game, Peter? You made your debut here some months ago, and it’s too bad you’re back with your WUWT bullshit—–why don’t you go there where your “ignorance” is welcome?

For the “why should a bit of extra CO2 change that” I think, if memory serves, that there might actually be some “science paper” that actually says why. I think it’s likely all about “physics” and “molecules” and “transverse electromagnetic radiation” and all that stuff that led to the development of heat-seeking guided missiles and the suchlike, or it might just be magic. Check it out if you can find the time sometime.

I studied engineering at University of Wales and as I interpret this article that makes me most qualified to try the Peter Irvin Smith experiment where I put ice, water & vodka in a glass and keep adding ice and sipping it for a few hours to see whether all the ice will fall off Antarctica or not. I’m getting started on that this evening.

At least grindupbaker has inserted some rare humour in this debate(both posts? I’m not sure about the first) – far preferable to the rancorous insults from dumboldguy of whom I had made no major criticism.

For your information, I was predicting climate change long before it became fashionable let alone an enforceable religious belief – only not your sort of climate change. The more I have studied over decades the more certain I have become. Whether or not man-made CO2 has helped to warm the earth or not makes no difference to my basic theory – so I am not a denier as far as that goes. If it has, then it has has sped up the process and is bringing the end of the inter-glacial phase to pass sooner than would otherwise have been the case, but a few degrees warmer cannot have the negating effect that you suggest because global temperature in itself has nothing whatsoever to do with the tipping point that ends the present phase.

It is such a pity that you ignore the science – in fact you do not even ask for clarification – and show no respect for other points of view but instead make wild and inaccurate assumptions and accusations. It is this standard practice of global warmers that makes others so distrusting of all the so-called science and projections. If your science is so incontrovertible why do you all have to abuse those who think otherwise? In point of fact I dislike the burning of fossil fuels as much as you do, though I am far more concerned about particulates than CO2.

Just for fun, explain this: from about 3100BC to 1800BC Stonehenge was being built and rebuilt and there was a very considerable population on the open hills of Salisbury Plain and also on the tops of Dartmoor and Bodmin Moor and there was a very important centre of astronomy and authority in the Orkney Islands (North of Scotland at 59dg north). Obviously the climate then was much warmer and far less cloudy than at present for the necessary detailed observations are impossible now and no-one lives on those hills now, even in modern insulated houses, let alone stone and turf huts. So if Western Europe, at least, was so much warmer then than now, why was that period not followed by the terrible prospect you assure us is about to visit the planet? If 1200 years of very warm didn’t bring disaster, why is much less warm for a much shorter period going to do it now?